Cooling device for motion-picture machines



APPLICATION FILED MAY 19, I919- Patented Fb. 28, 1922.

UNITED STATES CHARLES FRANCIS JENKINS, 0F

cooLme nnvron ron Specification of Letters Patent.

WASHINGTON, DISTRICT OF COLUMBIA.

MOTION-PICTURE MACHINES.

Patented Feb. 28, 1922.

Application filed Kay 19, 1919. Serial No. 298,265.

To all whom it may concem:

Be it known that I, CHARLES Framers JENKINS, a citizen of the United States, and resident of Washington, in the District of Columbia, have invented certain new and useful Improvements in Cooling Devices for Motion-Picture Machines, of which the following is a specification, reference being had therein to the accompanyin drawing.

In motion picture exhiblting, safeguarding against fire is of enough importance to warrant employing entirely distinct expedients in the same machine so that assurance of safety may be doubly sure under any and all possible conditions. Many expedients have been devised some limiting combustion to a single picture, some reduclng the temperature of the light beam, some running in open air a. shutter between the lamp and film, some in one way or another limiting combustion to the short length of film at any one time outside fireproof reel chambers, some mal atmosphere, chilled air,

cutting off light whenever the film stops or is reduced in speed. 4

This invention employs, either alone or in connection with one or more of other devices for similar purposes, a cool air blast over the film at the exposure point, the air being noror highly compressed air allowed to expand 'ust before it reaches the film and so reduced in temperature.

In the accompanying drawings,

Figure 1 is a vertical section looking toward the edge of the film at the exposure opening.

Figure 2 is a section on the line 2--2 of Fig. 1.

' As shown, A represents a plate having an exposure opening at B, C a film passed across the opening in any suitable way, D

under any desired chamber discharg- (prassage F, across the face of the film, and a valved conduit leading from the reservoir D to the chamber E where the air is allowed to expand, if it be under material compression.

When the machine is in operation the valve is opened so as to allow the desired stream of air to pass into the chamber E and thence upwardly over the face of the fi a chamber holding air tension, E an expansion ing, by a 1m and across the patli of the light beam advancing in the direction of the arrow :20. The air readily escapes from the usual casin or box, but the box is not necessarily without special air exits.

What I claim is:

1. In a motion picture the combination with a an exposure opening, picture film along one face of the plate an across said opening, of an air-expansion chamber discharging across said opening through a transversely narrow elongate slot, and means for supplying materially compressed air in said chamber, whereby air cold through expansion may pass in an even thin stratum across the path of light to the film.

2. The combination with a plate having the usual light opening across which motion picture film is fed in projecting, of an air expansion chamber at the face of the plate alongside said 0 enin and closed except for a narrow slot a apte to discharge a broad thin film of air across the opening, controlled means for discharging compressed air in said chamber.

In testimony whereof I hereunto aflix my signature.

CHARLES FRANCIS JENKINS.

projecting machine, fixed plate having of means for feeding 

